Manufacture or treatment of artificial materials



June 11, 1935. H. DREYFUS 2,004,274

MANUFACTURE OR TREATMENT OF ARTIFICIAL MATERIALS Filed May 4, 1932 HENRY DRE YPUS 3% M MANUFACTURE i Q FJ C on TREATMEN'IIOFM ARTIFICIAL MATERIALS p Ilenry Dreyfus, London, England Application May4, 1932, Serial-No. 609,253 f In Great Britain June 4,1931 H This-invention relates to the manufacture or treatment of textile yarns or threads, and par ticularly to the treatment of yarns containing continuous; filaments, e. g--.- artificial yarns of -6 cellulose acetate or other cellulose derivatives,

such as cellulose formats, propionate, andbutyrate, or cellulose 'ethers, such as T ethyl, methyl and benzyl cellulose. I The principal object of the invention is to 1 ensure that yarns of the above character maintain the fullest strength possible during anyoperations in which they are employed-including' the step of manufacturing such yarns.

Primarily, the invention seeks toovercome or 1- reduce any straining of the yarn arising from any tendency of the yarn to shrinkafter-theyarn has been wound into packages or during winding.

It has been found that when cellulose derivativeyarns have beensubjected to a stretching 20- operation for the purpose of increasing their strength as described in U, S. Patent No. 1,709,

470, applications S. Nos. 378,684: filed lfith July 1929, 403,140 filed 28th0ctober 1929, 573,424

filed 6th November 1931, and S. No. 605,184

251 filed 13th "April, 1932 corresponding to British application No.-13,373/31 filed 6th May 1931', this stretching taking place-beyond the elastic limit of'the yarns, there is a tendency for a portion of the extension thus imparted to be re- 30, covered more or less gradually after the stretching operation has been completed, with the resultthat if the yarns are maintained under tension duringrsuch contraction e g. on a compact package, by the firmly wound adjacent 35;, layers of yarn there is the danger of theyarns being strained and weakened. Likewise, high twisting of such yarns as is-employed, for example, in the production of crepe yarns results in the yarn,-.either by the modified structure of the yarn resulting from the high twisting of the component'filaments, or by some or all of the filaments being. stretched during the twisting process, tending to contract in length on being stored, with the similar danger that the yarns ,5,, may be strained if kept under [undesirable tension. I I

In either of the cases just mentioned this tendency to contract may be appreciablyincreased if the yarns have been treated with'wa- 50; ter or other solvent or swelling agents for the cellulose acetate or other cellulose derivative during the treatment, even though the yarns have been dried before winding. Similarly, in

after the treatment, whether by reason of a residuum of contracting agent remaining; in.

the yarn or even after the agent has been -re-] 6 5 moved, takes place and adversely afiectsthe- '.bypermitting the contraction to take place While other package on to which the yarn'is wound,

yarn if the yarn is maintained unduly tensioned. This contraction maytake'place even after drying of the yarns. It also happens thateven with yarn wound as'the fihal step of the spinning cperationwhether by thedry or evapOra- I tive or the wet or coagulation method or a combination of these two methods,the presence of residual solvent in the yarn produces a tendency for the yarn to contract after it has become set, becausethis solvent evaporates fromthe-yarnr Thedisadvantage arising in' thisnway may," apart from weakening the yarns-,"result in un-f evenness of the yarns because of unequalcontraction taking place along the length of the yarns or throughout the bulkor packages containingthe yarn." I

It now been-ifound that 'any deleterious result which might arisej from this tendency to contract can be. avoided or atany rate reduced I theyarn is not under substantial tension soasto reduce any tendency towards straining of the yarn. For this purpose contraction may beallowed to take place upon the bobbin, beam, or

byslackly winding the yarn thereon, so giving it freedom. to contract on the package without it being subjected to strain, since undue-tension is avoided. Thus, for example, in themanufacture of=- cellulose derivative yarns, e. g." by the dry or evaporative method, the yarn may be drawn from the jet-in the usual way by a feed roller -whichdet'ermines the rate of production and thedenier of the yarn, and then takento a, winding apparatus which-builds the yarn into a package, the linear speed of winding being slightly below the linear speed of the feed roller; though not sufiicientlybelow for there to be anydanger of yarn accumulating between they feed roller and the package. 1 Thus a "drum. winding 40 device maybe employed inwhich the speed of the drum determines therate of winding of the yarn on I apackage-whose surface is pressed against/the drum, and the linear speed .ofthe drumis adjusted ,e. g. by means Of'a variable friction drive," to feed roller; I a

In order to takefulladvantageof the slack: winding, cross-winding ofthe yarn on the package may be resorted" be slightly below that of the V a somewhat ope'n character; a In order to ensurethat whatever contraction which tends to take place doels" so s ufliciently early to avoid excessive tensitiningof theyarn, the yarn may be wetted with water or dilute solutions of solvents'or swelling agents for the cellulose derivative before the yarn reaches the Winding apparatus, in suchncas es the yarn may also be passed overor througha drying device.

after wetting and prior to winding; r

o,'so giving the package ages than bobbins.

Apparatus for slackly winding the yarn as described above may be used otherwise than continuously with the production of yarns of artificial filaments, and yarns'may be treated by similar methods, duringwinding on other pack- Thus, for example, the yarns may be wound slackly continuously with stretching in a bobbin to bobbin operation; or continuously with the twisting of the yarn toa high degree. Or again, where a number of yarns are stretched in the form of a warp, the beam on which they are wound after stretching can be driven at such a speed that the warp is. slackly wound theron. Further, such slack winding may take place otherwise than continuously with stretching or twisting, the yarn being wound after such operation on a hank for example, and then taken from the hank and rewound slackly on to a bobbin'or other package.

When the yarn is'stretched before winding, shrinkage may be encouraged to some extent by wetting the yarn, and if desired drying it again prior to winding. Again, in a twisting operation the yarn may be wetted'before or during j twisting, or, as described in U. S. application S.

No. 611,922 filed 17th May, 1932 corresponding to British application No. 16,405/31 dated 4th June 1931, between stages of twisting, and may be Wound either in a wet state or after drying. Further, the yarn may be treatedbefore, during or after twisting in the manner described in U. S. applications S. Nos. 610,702 and 610,703 filed 11th April, 1932 corresponding to British application No. 14,399/3l dated 15th May, 1931, according to which a substanceis formedby chemical reaction within the thread to produce shrinkage. The treatment according to U. S. applications S. Nos. 610,702 and 610,703 corresponding to British application No. 14,399/31 may be carried out in such a way as to cause shrinkage either before or after winding has been effected.

Winding of the yarns in the manner above described may with advantage be employed in conjunction with the sizing processes described for the production of crepe yarnsof cellulose acetate or other cellulose derivatives in U. S. applications S. Nos. 491,070 filed 24th October 1930, 514,898 and 514,899 filed 10th February 1931, 530,728 filed 16th April 1931, 527,358 filed 2nd April 1931, and 535,287 filed th May 1931, as Well as with the processes of producing crpe yarns of cellulose acetate or other cellulose derivatives described in US. applications S. Nos. 523,930 and 523,931 filed 19th March 1931, 550,716 filed 14th July 1931, and 559,210 filed 25th August 1931. Such yarns may be used in the swelling process for crepe fabrics described in U. S. application S. No. 50l,161 filed th December 1930. The winding method according to the present invention may also be used for winding the yarn described in U. S. applications S. Nos. 573,422 filed 6th November 1931 and 574,852 filed 13th November 1931.

As has been mentioned above, slack winding of the cellulose derivative yarns can be employed after stretching of the yarns in hank form, thus enabling contraction to take place freely on'the wound package. Instead, however, of

' winding the yarns, hanks of yarns which are 1 which regulates the shrinkage to an amount which may be permitted. After contraction has taken place, the yarns may be wound from the hanks, without, however, it being necessary to wind them slackly. If such yarns are then twisted, the precautions above indicated should again be taken to avoid undue tensioning on the subsequent contraction taking place.

In view of the increased strength of yarn obtainable by the invention, or at any rate the prevention of any serious diminution of strength arising from contraction of the yarn, yarns produced according to the invention are of value whatever their. application in the textile industry. Thus in their application to crepe fabrics, they may be used not only when highly twisted as weft or warp or both, but with a lower twist, as for a low twist warp to be used with a high or very high twist weft. The advantage arising from the invention is particularly useful in the case of yarns of low denier, especially when highly twisted.

Though the invention has been described above particularly with reference to yarns of cellulose acetate or other cellulose derivatives, it is to be understood that it maybe applied to other artificial yarns, such as the reconstituted cellulose yarns, e. g. viscose, cuprammonium, and nitrocellulose silk, or to natural yarns such as natural silk, and may beemployed in conjunction with the treatment of such yarns described in the specifications mentioned above and in U. S. application S. No. 559,210 filed th August, 1931.

The invention will now be described in greater detail with reference to the accompanying drawing, but it is to be understood that this description is given byway of example only and is in no way limitative.

Figure 1 is a side elevation of means for collecting yarns continuously with their production, in the manner according to the invention.

Figure 2 shows means for carrying out the invention in a bobbin to bobbin stretching oper ation.

Figure 3shows means for applying the invention continuously with the stretching of a sheet of warp yarns.

Figure 4 shows the application of the invention during a twisting operation.

Figure 5 is a View of driving means for the take-up device of Figure 4.

Figure 6 shows an apparatus for drying yarns during collection, and

Figure 7 showsa method of carrying out the invention with a bank of stretched yarn.

Referring to Figure 1, a number of filaments of cellulose acetate or other organic derivatives of cellulose in ,the form of a thread 10 are taken from a spinning machine H by means of a roller 12 roundwhich the thread passes one: or more times. After leaving the roller 12 the thread 10 passes through a stationary thread guide 13 to a traversing thread guide M which leads the thread on to a' bobbin 15 on which it is collected. The bobbin I5 is driven by means of a drum [5 contacting with the thread with bobbin l5 and rotated with a peripheral speed slightly lower than that of the feed roller l2. The feed roller I2 determines the rate at which the filaments are produced from the spinning machine H, and collection takes place at a slightly lower speed determined by the peripheral speed of the drum I6, so that provision is made for contraction of the thread after wind-- ing on the bobbin l5. The bobbin i5 is mounted in such a manner that it can rise as the bobbin fills up, the drum I6 maintaining contact with the surface of the thread wound on the bobbin so as to keep the winding rate constant.

In Figure 2 the thread ID istaken'fr'om a bobbin [9 and is passed round a roller 29, after leaving which the thread l0 passes over a wick 2| applying thereto a liquid e.g. an aqueous solution of acetone, or, any other ofthe solvent liquids mentioned in U- S. application S. No. 378,684 filed 16th July 1929, adapted to exert a solvent or softening action on the thread. The

thread then passes round a second roller 22 which is geared to run at a. higher speed than that of the roller 20, so that the filaments of the thread l0 having been softened by theapplication of liquid from the wick 2 I arestretched between the rollers 20 and 22. After leaving the roller 22 the thread ID passes to a traversing guide l4 leading it on to a bobbin l5 driven by a drum l6 as described with reference toFigure 1. The drum [6 driving the bobbin 15 by contact with the yarn is rotated with a peripheral speed somewhat lower than that of the roller 22, though not so much lower as to permit the accumulation of the thread between the roller 22 and the guide l4. In this manner the thread 16 is slackly wound on the bobbin l5 and is free toshrink after winding.

In Figure 3 a sheet of threads 25 is taken from a beam 26 and is passed round a set of stretch,- ing rollers 21, 28, the threads 25 passing under the roller 21 and being nipped thereon by means of small rollers 28. The threads 25 then pass in a similar manner round a second set of rollers 29, 30 rotating at a higher speed than the first set 21, 28 so that the threads 25 are stretched as a whole between the two sets of rollers. If desired a washing liquor may be applied to the threads passing round the roller 29 by means of a trough 3|; After leaving the rollers 29, 30 the threads 25 are given a fairly long run before reaching a second beam 32 which is rotated at a peripheral speed somewhat lower than that of the rollers 29, 30. The

threads are thus kept slack between the rollers 29, 30 and the beam 32, and are slackly wound on the beam so that contraction may take place after winding. A drying plate 33 through which steam is caused to flow by means of supply and exhaust pipes 34, 35 may be provided in order to dry off the washing liquor applied from the trough 3|. i

In Figure 4 a bobbin 3'! is mounted on spindle 38 and is rapidly rotated thereon. The thread 99 is drawn from the bobbin 3'! and is passed through a floating ring 49 mounted on the spindle 68 in the manner described in U. S. Patent No. 1,784,581. Thethread then passes through a guide 4| in line with the spindle 38, and round a feed roller 42 to a collecting device [4, l5, l6.

A high degree of twist is imparted to the thread 39 while it is being drawn from the rapidly ro- 43 shown in dotted lines, and the yarn may be wound onthe bobbin l5 in a wet state if desired.

Figure 5 shows an adjustable driving mechanism suitable for driving the drum Hi. The

drive is taken from a pulley 45 to a small fric- 7 tion wheel 46 driving an intermediate disc 41,

which in turn drives a friction wheel 48, mounted on'the driving shaft of the drum l6. The

axis 49 of the disc 41 is adapted to be horizontally adjustable so that the radii at which the friction wheels 46, 48 act may be varied in order to vary the rate of driving of the drum l6. The bobbin I5 is mounted freely on a spindle 50 which rises as the bobbin fills, in the manner I described with reference to Figure 1. The driving mechanism described may be applied toa "single twisting and collecting device, but more conveniently is adapted to drive a series of drums l6 in order to collect the twisted thread I in order to produce some degree o-fshrinkage before twisting. For this purpose the apparatus shown in Figure 6 is suitabld'wherein the thread passing round the feed roller 5| is submitted to an aqueous bath contained in a trough 52,

and then passes down a tube 53 having a jacket 54 for steam, hot water or other heating mediuma After leaving the tube 53 the thread is collected by means of a twisting device having thread guides [3,14, a bobbin l5 and drum- I6 as described above.

In Figure 7a hank of yarn 51 which has been stretched in hank form, is mounted upon a reel 58 and is drawn therefrom by means of a feed roller 59. The thread passes from the roller 59 to stationary guide l3, a traversing guide I4 and bobbin 15 as described above. I which drives the bobbin I5 is caused to rotate at The drum I6 a speed slightly lower than that of the feed roller 59 so that the filaments are slackly wound on the bobbin [5.

In any. of the cases described above,in order to augment the effect of slackly winding the yarns,

collecting package supports may be used, e. g.

for the bobbin I6, which have resilient surfaces,

as described for example in U. S. application S. No. 569,251 filed 16th October, 1931.

, What I 1. Process of packaging set cellulose acetate yarn in a condition liable to produce contraction of the yarn after the same is wound on the package which comprises applying a liquid maclaim and desire to secure by Letters Patent is:-

terial to the "yarn to assist said contraction and winding the yarn on a package support rotated at a peripheral speed slightly lower than the delivery ofthe yarn to the package, so that the yarn is wound on the package in such a the yarn is wound on the package in such a manner that the yarn when contracted on the package is no longer slack and any tendency to strain the yarn is reduced.

1 HENRY DREYFUS.

manner that the yarn when contracted on the I 

